LAUSR

BACKGROUND Hepatosplenic T-cell lymphoma (HSTCL) is a rare subtype of non-Hodgkin’s lymphoma, which has an aggressive clinical course and an extremely poor prognosis. Chidamide is a novel, orally active, benzamide-type histone deacetylase (HDAC) inhibitor that has been used for peripheral T-cell lymphoma (PTCL) treatment. However, to date, there has been no report of the treatment and effect of the HDAC inhibitor chidamide in HSTCL, which is a special subtype of PTCL. CASE SUMMARY A 45-year-old male patient was admitted with splenomegaly and slight bicytopenia. He was diagnosed with HSTCL via splenectomy. The patient was treated with fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with high-dose methotrexate and cytarabine regiment as inductive therapy. Unfortunately, the disease progressed rapidly during chemotherapy before a suitable allogeneic gene transplant donor was found. The chidamide-combined chemotherapy regimen and single-drug oral maintenance regimen achieved complete remission, duration of response of 9 mo, and overall survival of 15 mo. CONCLUSION The novel agent chidamide can be used in HSTCL to achieve deep remission and improve the duration of response and overall survival.